function zeroFill(time) {
	return time < 10 ? '0' + time : time
}


export function countDown(nowTime,futureTime) {
	futureTime = 1800 * 1000 + futureTime
	if(futureTime <= nowTime) {
		return ''
	}
	let time = (futureTime - nowTime) / 1000
	let h = zeroFill(parseInt(time / 60 / 60 % 24))
	let m = zeroFill(parseInt(time / 60 % 60))
	let s = zeroFill(parseInt(time % 60))
	return h + ':' + m + ':' + s
}

